Updating a Datapack

Hey everyone. I found a datapack called "luminous end" on planet minecraft from a few years ago. The datapack was made for 1.18.2 so its a little outdated but the pack doesnt work. The placed_features and confugiured features and prob every single file is outdated and is missing stuff. How hard would it be to go through and update it to 1.21.10?
https://www.planetminecraft.com/data-pack/luminous-end-v0-9/